Microsoft Principal Architect Steve Peschka just finished up an interesting three-part series of posts on his Share-n-dipity blog that detail how to build a custom claims provider for SharePoint that uses Windows Azure as the data source.

At the end of this series, Steve says readers should have an end-to-end SharePoint-to-Cloud environment running on Windows Azure. This series includes proof of concept as well as complete source code that you can use as you wish.